I think that it's really hard when the grandparents don't support the decisions we make for our children. My parents believe that
(a) the school will never do anything for my child
(b) DD8 just needs to learn to deal with it
(c) She is not as unhappy as she says she is
(d) Grade acceleration is always wrong

With parents, I think it comes back to a bias towards the decisions they made when they raised their children. They're not living with our children so they don't see the frustrations up close, and it's been a long time since they had kids in school. I just hope that the testing we have done will give our concerns some unbiased validity. It hurts to have your own parents not support you, but relationships are even trickier with in laws, especially when you need them for help with child care.

Perhaps if you stand strong in your decision she will come around to accepting it in time.